1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device having a coupling structure.
2. Description of the Related Art
In general, an LCD device displays a desired image by individually providing a data signal to pixels arranged in a matrix configuration according to image information, thereby controlling light transmittance of the pixels. Accordingly, the LCD device includes a display panel where pixels are arranged in the matrix configuration and a driving unit for driving the pixels.
The display panel includes a thin film transistor array substrate and a color filter substrate bonded to each other by a uniform cell-gap, and a liquid crystal layer formed at an isolation interval between the color filter substrate and the thin film transistor array substrate. The display panel is provided with a common electrode and a pixel electrode to apply an electric field to the liquid crystal layer. Accordingly, if a voltage of a data signal applied to the pixel electrode is controlled in a state that a voltage has been applied to the common electrode, liquid crystals of the liquid crystal layer are rotated according to the electric field generated between the common electrode and the pixel electrode by dielectric anisotropy, thereby transmitting or cutting off light pixel by pixel to display text or an image.
In addition, the LCD device cannot emit light by itself, but can display an image by controlling transmittance of light. For this reason, the LCD device requires a backlight assembly for emitting light to the display panel. The backlight assembly is divided into perpendicular-type and edge type devices. In the perpendicular-type device, a lamp is disposed at a rear surface of the display panel and light is directly transmitted to a front surface of the display panel. In the edge-type device, a lamp is disposed at at least one side of the display panel, and light is reflected, diffused, and collected through a light guide plate, a reflection plate, and sheets to be transmitted to the front surface of the display panel.
As mentioned above, the LCD device includes the display panel and the backlight assembly. In order to support and couple the display panel and the backlight assembly, various elements have been utilized, which will now be described in detail with reference to accompanying drawings.
FIG. 1 is a schematic cross-sectional view of an exemplary LCD device according to the related art. Referring to FIG. 1, the related art LCD device includes a display panel 10 where pixels are arranged in a matrix configuration, a main supporter 20 for supporting a rear edge and a side of the display panel 10, a top case 30 coupled to a side of the main supporter 20 by pressing an upper edge of the display panel 10, and a lower cover 50 coupled to a side of the main supporter 20 by a screw 51 and supporting a backlight assembly 40.
The backlight assembly 40 includes a reflection plate 41 provided at an upper surface of the lower cover 50, a light source part 43 having a plurality lamps 42 disposed on the reflection plate 41 to make light incident onto an entire rear surface of the display panel 10, a diffusion plate 44 corresponding to the entire rear surface of the display panel 10 to cover the light source part 43 and having a rear edge supported by the lower cover 50, and an optical sheet 45 disposed at an upper surface of the diffusion plate 44. The display panel 10 and the optical sheet 45 have a predetermined gap therebetween by a protrusion of the main supporter 20.
In a case where an edge area on which no image is displayed (i.e., a bezel) is formed in a minimum size, the LCD device is fabricated with the upper edge of the display panel 10, covered with the top case 30 and the main supporter 20 that are formed in a minimum size in effort to make a light and small LCD device in the same sized model. However, the related art LCD device has following problems.
When the LCD device is fabricated to have the upper edge of the display panel, covered with the top case 30 and the main supporter 20 that are made in the minimum size, the square frame-shaped main supporter 20 for supporting a lower edge of the display panel 10 and its side is vulnerable to surface tension parallel to the ground. Thus, the display panel 10 and the optical sheet 45 of the backlight assembly 40 supported by the main supporter 20 become detached from the main supporter 20 and are damaged by the protrusion of the main supporter 20.
Therefore, the related art LCD device utilizes the screw 51 to couple the side of the main supporter 20 and the lower cover 50, or a double sided tape to adhere them to each other, whereby the square frame shaped main supporter bar 20 is not affected by the surface tension parallel to the ground. However, it becomes complex and difficult to assemble the LCD device because of an additional operation for coupling the side of the main supporter 20 and the lower cover 50 by the screw 51, or adhering them by the double sided tape to ensure that the square frame shaped main supporter 20 is not affected by the surface tension parallel to the ground. Also, this additional operation causes deterioration in productivity of the LCD device. Moreover, fabrication costs are increased due to usage of subsidiary materials such as the screw 51, the double sided tape, or the like.